Rigid inflatable boats (commonly known as "RIBs") have found increasing use in rescue operations, especially in heavy seas. Also, RIBs have proven capable of being launched and retrieved from larger vessels while the larger vessels are underway. RIBs have a rigid hull that normally is either of aluminum or GRP construction, are powered, and have an internally sectioned rubber ring (called a "tube") disposed substantially around the entire periphery of the hull generally at or above the waterline. These boats have remarkably good stability, buoyancy, speed, and resilience to crushing, in a wide variety of sea conditions.
Typically the inflatable components of RIBs are produced by labor intensive methods, by cutting and adhesively seaming elastomer-coated textile fabric, and are adhered to the hull by adhesives or other methods which do not facilitate the rapid mounting and demounting thereof. Since multiple chambers are provided in a common structure, repair is the sole alternative to total replacement, and is difficult. Also, such structures are difficult to stack for shipment or storage when the inflatable element is attached to the hull.
According to the present invention, a structure is provided that, in combination with a rigid hull of a boat, eliminates many of the drawbacks associated with conventional RIB inflatable elements, while still providing the necessary stability, resilience and buoyancy to the boat. According to the invention, a plurality of inflatable elastomeric material bladders are provided, the bladders being disposed in end-to-end relationship around substantially the entire periphery of the hull so as to provide a desired inflatable ring. Positioning means are provided formed with the hull for positioning each bladder with respect to the hull. The positioning means may take the form of a plurality of generally horizontally extending through-extending openings formed in the hull generally above the waterline. Holding means are provided cooperating with the hull positioning means and each of said bladders for holding each bladder to the hull at said positioning means when the bladder is inflated, and allowing ready demounting of the bladder from the hull when the bladder is deflated. Such holding means may take the form of a neck portion integral with the bladder, and an enlarged portion or rigid flange operatively connected to the neck. When the neck and the enlarged portion, or rigid flange, are passed through the hull positioning opening, upon inflation of the bladder they are maintained in contact with the interior surface of the hull and prevent detachment of the bladder from the hull.
According to the present invention, it is also often desirable to provide interlocking cooperating end portions of the bladders, such as V-shaped projections and troughs, spherical portions and spherical cavities, etc., to stabilize the positions of the bladder vis-a-vis each other and the hull. Further, it is often desirable to provide a shroud(s) surrounding each, or a plurality, of the bladders. The shroud(s) preferably is held to the hull by the bladder holding means.
It is the primary object of the present invention to provide an advantageous structure facilitating the constructions, deployment, and storage of RIBs. This and other objects of the invention will be come clear from an inspection of the detailed description, and from the appended claims.